Retractable composite impeller assembly

ABSTRACT

An extendable/retractable rotor for vertical lift has plural rotor blades, each with a rotor hub assembly, blade top and bottom hinged casings and a pitch disc rotateable about its longitudinal axis to change the rotor blade pitch angle. An interlink assembly has a blade base, a link base subassembly of top and bottom link hubs, two locking arms, a retracting reel assembly having exterior and interior rotor axles, a breaking actuator having plural outer breaking notches, plural recoiling spools forming a reel cage and a locking mechanism preventing blade retraction. A helical ribbon assembly with plural sequentially overlapped ribbons has pin restraints, plural layers each helically wound around the interlink assembly and a flexible and elastic sleeve of plural elastic ribs. An elastic and flexible skin made of composite elastomeric sheet reinforced by fibers is provided as is a zipper slider mechanism of a main slider, a zipper wedge, a wedge track, plural spring loaded wheels, plural hinged plates and plural hinge joints.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority on U.S. Provisional Patent ApplicationNo. 61/108,282, filed Oct. 24, 2008, which is also incorporated here byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates primarily to the field of aerospace andthe field of lift generating structures. More specifically the inventionrelates to the design of retractable rotor blades. Even morespecifically the present invention relates to the design of retractablerotor blades used as means to produce lift and thrust for vertical andshort take off vehicles.

2. Description of the Related Art

Rotor blades have been used for many years to achieve flight. A shortcoming of related art is that conventional rotor blades and rotor bladeassemblies have longitudinally rigid structure (U.S. Pat. No.7,475,847). Many rotor blades are now made of carbon fiber, fiber glassand other composite materials. These conventional composite rotor bladesand composite rotor blade assemblies are manufactured to be used asrigid structures, not capable of being collapsed to a smaller volume(U.S. Pat. No. D 580,344). In order to be effective conventional rotorblades often require very large rotor blade spans. Large rotor bladescustomary in VTOL (vertical take-off and landing) and STOL (shorttake-off and landing) vehicles typically require large storage space tohouse them.

In other examples of related art, rotor blades are designed toreconfigure into a more stowable state (U.S. Pat. No. 6,176,679). Thisis often because they are to be housed indoors when not in use, or as anattempt to reduce the breadth of the rotor blade's slipstream whentransported. Another example of related art is the ability for somerotor blades to be capable of folding onto themselves (U.S. Pat. No.4,086,025). Another example of related art is the ability for some rotorblades to be retracted using a telescoping system (U.S. Pat. No.6,972,498). The aforementioned example is made retractable by concentrictelescoping solid rotor blade cross sections. A short coming oftelescopically retracted systems is that they require each subsequentsection of the rotor blade to be of a different dimension than thepreceding one. This reduction of dimension and non uniformity of theblade sections creates aerodynamic instabilities and it is notdesirable.

Since the development of the airplane there have been many attempts tocombine the ability of a flying vehicle with that of an automobile (U.S.Pat. No. 7,481,290). One particular example of such a vehicle hasfolding wings (U.S. Pat. No. 7,462,015). Another vehicle examplerequires the user to completely remove the lifting surfaces from thevehicle when being used as an automobile. Other examples of related artincorporate road vehicles equipped with full scale aircraft wings. Otherexamples of related art use rotor blades which fold upon themselves(U.S. Pat. No. 7,584,923). These designs are too cumbersome and do notprovide the required compactability of the rotor blades to be usedpractically by road worthy vehicles. Some examples of related art usefan blades to generate lift, but these require the fan blades to beoperated at higher rpm. The requirement for higher rpm is due mainly tothe small dimensions of the fan blades. Another example of related artuse fabrics as the exterior surface of the blade which is exposed to theairstream (U.S. Pat. No. 4,411,398).

Other objects and advantages of the present invention will becomeapparent from the following descriptions, taken in connection with theaccompanying drawings, wherein, by way of illustration and example,embodiment of the present invention is disclosed.

SUMMARY OF THE INVENTION

In accordance with the preferred embodiment of the invention thefollowing describes a retractable composite impeller assembly. Theprimary difference between the present invention and related art is thatconventional rotor blades and rotor blade assemblies have longitudinallyrigid blades. And unlike telescopically retracted systems the presentinvention does not require each subsequent section of the rotor blade tobe of a different dimension than the preceding one. The presentinvention also does not restrict the length of the blade. The currentinvention allows for controlled dynamic deployment of rotor blades. Thepresent invention also increases the speed and precision with which theblades can be retracted and deployed. The present invention makes itpossible to make retractable fan blades.

The present invention includes major and minor components, assembliesand subassemblies arranged such that together they form a mutuallyreinforcing structure capable of being deployed to generate the requiredforces for flight and retracted to a considerably smaller volume whennot in use or stored. Another object of the invention is that a vehicleequipped with the current invention will be capable of vertical takeoffand landing. In its retracted state the current invention will make itpossible for the vehicle to travel along automobile roads of standarddimension. The constituent components and subassemblies may becomprising of multiple instances of similar or dissimilar materials andemploy the most desirable characteristics of each material.

Due to improvements made in the area of composite materials the presentinvention employs these materials to create retractable blades which donot require manual manipulation or removal of any part of the system inorder to work. By using flexible and strong composite to bear theprimary stresses during operation the present invention reduces theloads experienced by the remaining rigid support structure andconsequently reduces the amount of creep experienced by the system.Composite materials are exceptionally well suited at resisting tensilestresses and so are ideal materials for this application. Typicalcomposite materials include but are not limited to carbon and glassfibers, elastomers, aramids and other high strength polymers. Anotheradvantage of the present invention is its ability to be refitted orrefurbished with very little modification and limited part replacement.In other words if the exterior layers of the present invention aredamaged they can be easily replaced with out needing to replace theentire system and at a considerably lower cost than conventional rotorblades.

The primary components and assemblies of the present invention mayinclude an impeller blade assembly, a rotor hub, rotor axle assembly,retraction reel assembly, a blade internal support structure, a releasecable assembly, a helical ribbon assembly, an exterior sleeve assembly,a blade casing assembly, and an extendable zipper mechanism. A rotoraxle serves as an axis of rotation and to transmit torque to theretractable composite impeller assembly. The purpose of the impellerblade assembly is to generate lift when in operation. The rotor hubprovides a structure on to which the impeller blade assembly isconnected. The rotor hub also houses a pitch disk through which torqueis transmitted to the impeller blade assembly such that the angle ofattack of the impeller blade assembly is able to be altered.

The components of the impeller blade assembly have a characteristicaerodynamic profile and/or are capable of conforming to such a profile.The impeller blade assembly may include a blade base, an interlink baseassembly, helically wound ribbon, and a flexible sleeve.

The purpose of the blade base is to connect the rotor hub to theinterlink base assembly. In one possible embodiment of the invention thepurpose of the interlink base assembly is to form a rigid structure overwhich a flexible sleeve can be fitted. In a second possible embodimentof the invention the interlink base assembly is also fitted with aplurality of helically wound ribbon. The purpose of the helically woundribbon is to reinforce the interlink base assembly and form a rigidstructure over which a flexible sleeve can be fitted. Another purposefor the helically wound ribbon is to constrict, lock and rigidify theinterlink base assembly when it is in use and allow the interlink baseassembly to retract when not in use.

The interlink base assembly may include a plurality of link basesubassemblies.

In one possible embodiment of the invention each link base subassemblyis comprising of a rigid aerofoil shaped cross section and mechanicallinkages. In a second embodiment of the invention each link basesubassembly also includes hinged plates. Each link base subassembly ismechanically connected to another link base subassembly through linkagesto form a longitudinally connected structure capable of being stackedone atop the other. The rigid aerofoil shaped cross sections are stackedone atop the other and mechanically connected to allow them to separatewhile remaining one assembly. Each link base subassembly is equippedwith a locking mechanism in order to ensure rigidity of the entireinterlink base assembly when deployed. Each locking mechanism can beactivated independently or simultaneously by a release cable. Therelease cable is part of the retraction assembly which is housed in therotor hub.

In one possible embodiment of the invention the flexible sleeve iscomprising of elastic ribs, an elastic and flexible skin and an elasticsling membrane. In a second possible embodiment of the invention theflexible sleeve can include a resealable elastic trailing edge. Thepurpose of the flexible sleeve is to be the outer most layer of theimpeller blade assembly as such it is exposed to the airstream. Theflexible sleeve also serves to reinforce the impeller blade assembly andprovide a smooth exterior surface for the impeller blade assembly. Theflexible sleeve may be constructed of woven, braided or elastomericmaterial to form a covering for the cross sections and mechanicallinkages of the interlink base assembly. In a second embodiment of theinvention with the use of the elastic trailing edge the impeller bladeassembly is equipped with an extendable zipper mechanism. The purpose ofthe extendable zipper mechanism is to separate and also to reseal anupper and a lower section of the elastic trailing edge. The purpose ofthe blade base casing is to house the impeller blade assembly whenstowed. It is to be understood that the present invention can also beused to form a wing. That is to say it can be easily modified to be usedas a wing of an airplane.

BRIEF DESCRIPTION OF THE DRAWINGS Definition of Orientation

The drawings of the invention have been illustrated in agreement withthe preferred embodiment of the invention. The figure numbers labeledthroughout this document are located below the figures they refer to.

FIG. 1 is a top view of the rotor in its extended condition comprisingthree rotor blade assemblies;

FIG. 2 is a top view of the rotor in its retracted condition showing theinternal assembly components of one rotor blade;

FIG. 3 is a top view of the rotor assembly showing the major assemblieswhich are common to each rotor blade and have been shown hereindividually for clarity;

FIG. 4 is a top view of the rotor assembly in its retracted conditionshowing the major assemblies which are common to each rotor blade;

FIG. 5 is a perspective view of the rotor assembly showing the internalcomponents of the rotor hub and showing the internal components of themajor assemblies which are common to each rotor blade;

FIG. 6 is a perspective view of rotor assembly showing release cables;

FIG. 7 is a perspective view of the recoiling reel assembly and showingoutline of pitch disc;

FIG. 8 is a perspective view of rotor assembly showing behavior of themajor assemblies in their retracted condition;

FIG. 9 is an isometric view of one rotor blade assembly in its retractedcondition showing hinge connections between the blade casings to the hubwall and zipper slider mechanism;

FIG. 10 is a pair of end tabs arranged such that they do not interferewith each other during retraction and showing one possible direction ofthe torsional spring force;

FIG. 11 is an isometric view of retractable internal skeleton showingmajor components with several hinged plates removed to show internalcomponents;

FIG. 12 is a perspective view of one link hub subassembly showing themajor components;

FIG. 13 is a partial, top, perspective view of link-base subassemblyshowing components and function of the internal locking mechanism andrelease cables;

FIG. 14 is an isometric front view of link-base hub 40;

FIG. 15 is an isometric back view of link-base hub 40;

FIG. 16 is an isometric view of interlinkassembly in its retractedcondition showing the mechanical operation of retractable links;

FIG. 17 is an isometric front view of link-base hub showing the hubledge;

FIG. 18 is an isometric rear view of link-base hub showing hub ledge andpneumatic dampener in its collapsed condition;

FIG. 19 is a top section cut view of the internal components of onerotor blade showing the components which act to retract the system;

FIG. 20 is a side section cut view of rotor assembly showing themechanical arrangement of the retraction assembly including releasecables in extended condition;

FIG. 21 is a side view of the rotor blade assembly showing the locationof zipper slider mechanism when system is retracted;

FIG. 22 is an isometric front view of the internal skeleton wrapped bythe helically wound ribbon;

FIG. 23 is a view normal to the span of the lifting body showingcrossection of the rotor blade and showing the characteristicaerodynamic linkage of the lifting body;

FIG. 24 is an isometric view of the construction of the flexible sleeve,elastic membrane and zipper closure showing and how they are joined;

FIG. 25 is an isometric view of the flexible sleeve in its retractedcondition showing an additional embodiment of the elastic membrane;

FIG. 26 is an isometric trailing edge view of elastic skin showingrepresentation of composite fiber helical weave pattern;

FIG. 27 is a trailing edge view of elastic skin showing representationof composite fiber weave pattern and buckling pattern of elastictrailing edge;

FIG. 28 is an isometric view of the end cap of elastic trailing edgeshowing hook and hollow geometry;

FIG. 29 is an enlarged section view of pin connection between helicallywound ribbon and internal skeleton;

FIG. 30 is an enlarged isometric view of elastic trailing edge end capshowing tongue and groove geometry;

FIG. 31 is an enlarged isometric view of tongue and groove geometry;

FIG. 32 is an isometric rear view of the configuration of the zippertooth closure and zipper slider function;

FIG. 33 is a front axial view of a zipper slider of the invention;

FIG. 34 is a rear axial view of a zipper slider of the invention;

FIG. 35 is a side view of the zipper slider of the invention;

FIG. 36 is a front axial view of another embodiment of the zipper sliderof the invention showing zipper slider ring bearing;

FIG. 37 is a rear axial view of another embodiment of the zipper sliderof the invention showing zipper slider ring bearing;

FIG. 38 is an isometric trailing edge view of the elastic skin showingcomposite construction of a rib-reinforced polymer matrix in the shapeof an airfoil;

FIG. 39 is a top view of the rotor blade assembly showing blade base.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A technical description of the major subassemblies of the invention willfollow,

02. Rotor Blades:

Referring to FIG. 1 and FIG. 2 the retractable composite impellerassembly embodiment comprising of two, three, or plurality of rotorblades 02 is depicted. FIG. 1 also shows the retractable composite rotorassembly of a first preferred embodiment comprising of the majorsubassemblies and in its fully extended condition. The geometry of rotorhub 10 corresponds to the plurality of rotor blades 02. In thisconfiguration each rotor blade assembly 02 experiences the samecentripetal force during rotation and deceleration.

Referring to FIG. 1 thru FIG. 4, the major subassemblies which arecomprising the present invention work in concert to allow the rotorblade 02 to have the ability to become extended when the system isrotated, and contracted when the system is forced to come to rest and ina controlled manner by way of a retracting reel assembly 13. The primarysubassemblies interface with each other in such a way that they transmitthe loads developed during rotation and act to reinforce each otherthereby strengthening the system as a whole.

Referring to FIG. 3 and FIG. 4, each rotor blade 02 is comprising ofidentical components and subassemblies with the exception of componentsand subassemblies of rotor blade 02 which are shared by way of rotor hub10 and retracting reel assembly 13. Referring to FIG. 1 thru FIG. 4 andFIG. 11, the major assemblies which make up the rotor blade assembly ofthe present invention are the rotor hub 10 having within it a retractingreel assembly 13, the interlink assembly 11 which is comprising of ablade base 30 and a plurality of link base subassemblies 12 and isconnected to the exterior of the rotor hub wall 20, a helical ribbonassembly 14 which is wrapped around the interlink assembly 11, aflexible and elastic sleeve 15 which envelopes both the helical ribbonassembly and the interlink assembly 11, and a zipper slider mechanism 16which encompasses the flexible sleeve 15 and serves to open and close aclosure located at the trailing edge of the flexible and elastic sleeve15.

Several components of the present invention are standard mechanicalparts which are ubiquitous. These standard parts include helical springs03, torsion springs 04, bolts and screws 05. Their usages throughout theinvention is apparent to anyone skilled in the art related to thepresent invention. Standard parts which share the same label areinstantiated throughout the various subassemblies of the invention.Wherever they are referenced it is to convey that they perform the sametype of function and can be used in different locations.

The retraction reel assembly 13 is mechanically connected to componentswhich make up the rotor blade assembly. When the system is rotated aboutthe interior rotor axle 72 shown in FIG. 20 a centripetal force isdeveloped about the central axis which forces the components which arefree to move to be extended radially outward from the axis of rotation.When the system is brought to rest by the retraction reel assembly 13and breaking actuator 73 each component of the rotor blade 02 which isconnected to the retraction reel assembly 13 by way of release cables 70is pulled radially inward towards the central axis 72. This is theprimary operation which enables the system to be extended or retracted.

10. Rotor Hub:

The rotor hub serves as the main structure to which each rotor blade 02is connected. It also houses the retraction reel assembly 13, anexterior and an interior rotor axle 71 and 72 and breaking actuator 73where the exterior and interior rotor axles share the same rotation andimpart torque to the entire rotor system. The rotation of breakingactuator 73 is allowed to be neutral when not engaged. Referring to FIG.5 thru FIG. 9, the rotor hub 10 is comprising of a rotor hub wall 20which has at its upper edge a hinged top casing 21 and has at its bottomedge a hinged bottom casing 22. The rotor hub wall also has through it apitch disc 23. Pitch disk 23 is able to rotate about its longitudinalaxis and has a moment arm 25 and connected to the moment arm isconnected a push rod 24. The rotor hub also has a top casing 26 and abottom hub casing 27. Referring to FIG. 6, FIG. 8, FIG. 9 and FIG. 11,one extremity of push rod 24 is connected to the pitch disc 23 by a balland socket connection through moment arm 25 and the other extremity ofpush rod 24 may be connected to a rotating swash plate. As push rod 24is moved up or down it causes the pitch disc 23 to rotate. The rotationof the disc is transmitted to the interlinkassembly 11, thereby changingthe angle of attack of the rotor blade. When the rotor is retracted, theelastic and flexible sleeve 15 is stowed within hinged casings 21 and22.

Referring to FIG. 7 and FIG. 19, pitch disc 23 has a circular groovewhich allows it to be held in place by rotor hub wall 20 while remainingfree to rotate along its longitudinal axis. Pitch disc 23 and blade base30 are axially coincident and have a common faying surface by which theyare rigidly or mechanically connected. Referring to FIGS. 9 and 20 tophinged casing 21 and bottom hinged casing 22 are connected at the bottomand top edges of the rotor hub wall 20 by means of hinge connections.The purpose of rotor axle 71 (FIG. 21) is to provide torque toretractable composite rotor assembly of the present invention.

Referring to FIG. 19 thru FIG. 21, the casings 21 and 22 are opened andshut by means of hinged connections to the rotor hub wall 20. Uponrotation of the system each hinged casing 21 and 22 is affected by thecentripetal force of rotation and is caused to be shut in theconfiguration shown in FIG. 20. Upon deceleration a potential springforce located at the hinged connections to the rotor hub wall 20 causethe blade casings 21 and 22 to return to their opened configurationshown in FIG. 21. The blade casings 21 and 22 serve two major functions.They serve to stow the retracted blade assembly and to engage the zipperslider mechanism 16 which contributes to the collapsibility of thesystem. Activation of the zipper slider mechanism 16 is made possible byeach casing 21 and 22 being simultaneously hinge connected to the hubwall 20 and to hinged plates 116 and 117 of the zipper slider mechanism16. When the casings 21 and 22 are rotated about their connection to thehub wall a rotation about hinge connections 28 and 29 is also developedwhich then causes translation of the main zipper slider 110. Mechanicalsprings can also be located at connections 28 and 29 to assist theoperation of the zipper mechanism.

11. interlinkAssembly:

Referring to FIGS. 10, 11, 12, 15, 19, 23 and 39, the interlinkassembly11 is comprising of a blade base 30 having a plurality of pin joints 31and guide notches 34 and blade base rectangular slots 35 and thru hole38 and characteristic profile 32, a pneumatic damper and cable casing 33having collapsible corrugated geometry 36 and a slotted cylindricalsection 37, a plurality of link base subassemblies 12 which are repeatedsimilar to links in a chain.

Referring to FIG. 11, the interlink assembly 11 can be thought of as achain comprising of a base connected to repeating links. Where eachrepeated link is referred to as a link-base subassembly 12. Referring toFIG. 11 thru FIG. 18 and FIG. 39, at one extremity blade base 30 ismechanically connected to pitch disc 23 and at its other extremity isinterconnected to a first link base subassembly 12 by way of rectangularbase slots 35 and hub hinges 50 of a first link-base subassembly 12. Inother words rectangular base slots 35 located at one extremity of bladebase 30 serve as sockets for hinges 50 which are part of link-basesubassembly 12. The link-base subassembly 12 is the fundamentalstructure which forms the interior structure of the rotor blade 02.Where one end of a first link-base subassembly 12 is connected to theblade base 30 and the other end of the link-base subassembly 12 isinterconnected to a next link-base subassembly 12. Referring to FIGS. 5,11, 22, 23 and 39, the interlinkassembly 11 forms a retractable internalsupport frame or internal scaffolding for the helical ribbon assembly 14and flexible and elastic sleeve 15 such that when both the helicalribbon assembly 14 and elastic and flexible sleeve 15 envelope theinterlinkassembly 11 and are in their extended conditions they form arigid assembly with a characteristic airfoil profile.

Referring to FIGS. 12, 13, 17 and 18 the pneumatic damper 33 has twomajor features which enable its function; a collapsible corrugatedgeometry 36, and a slotted cylindrical section 37. The slottedcylindrical section 37 has two notches which allow release cable 70 topass through these slots and be connected to locking arms 45 which arehoused within link hub 40 of link base subassembly 12. The slottedcylindrical section of damper 33 is clasped within link hub 40 therebyensuring that during extension or retraction of the system only thecorrugated section of the damper is collapsed or elongated. Thepneumatic damper and cable casing 33 serves two major purposes. Itserves as a cable housing for release cable 70 and as a damper whichopposes the motion of interlinkassembly 11 when it is extended orretracted. This allows for a more smooth deployment of the rotor blades.The pneumatic dampener 33 can also serve as an elastic spring.

Referring to FIG. 4, FIG. 8, FIG. 9, FIG. 12, FIG. 16 and FIG. 20,retractability of the system is achieved when each link-base subassembly12 is translated along the span of the rotor blade such that eachsubsequent link-base subassembly 12 becomes stacked one atop the otherwhile remaining connected to the next link base subassembly 12. This isachieved by way of retractable links 46 and 47. In other wordsretractable links 46 and 47 are the means by which each subsequentlink-base subassembly 12 is interlinked. This is accomplished by way ofhinged connections between link hinges 57 to hinges 50 of link hub 40and by passing linkages 46 and 47 through slotted openings 55 of asecond link-base subassembly 12 as shown in FIGS. 15 and 16. Inaccordance with a preferred embodiment of the invention upon retractioninterlinkassembly 11 reconfigures from the configuration shown in FIG. 3to the configuration in FIG. 4 and in both states remains oneinterconnected assembly.

12. Link Base Subassembly:

Referring to FIGS. 11-18, the link base subassembly 12 is comprising ofa top link hub 41 which has a slotted pin joint 51, and a bottom linkhub 42 where link hub 41 and link hub 42 together form link hub 40 andform a through hole 43 and hub ledge 59 and link head grooves 53 and hubhinges 50 and slotted socket openings 55 and threaded screw holes 56 andcharacteristic profile 32 and contains two locking arms 45 and has aplurality of plate hinge sockets 58; link base subassembly 12 is alsocomprising of a first retractable link 46 and a second retractable link47 both with a curved profile 48 and locking ledges 49 and link heads 52and link hinges 57; a plurality of hinged plates 44 which are hinged tolink hub 40 by way of hinged connections between plate hinges 54 andplate hinge sockets 58.

Referring to FIG. 13 thru FIG. 18, the link hub 40 is shown to becomprising of two sections, a section which forms the top of the airfoil41 and a section which forms the bottom of the airfoil 42 which are heldtogether by way of screw holes 56. Screw holes 56 also serve to fastenlocking mechanism 60. Retractable links 46 and 47 are allowed to slidewithin hub 40 by way of slotted socket openings 55 and are preventedfrom sliding out during rotation by way of mechanical interferencebetween link head grooves 53 and link heads 52. In this way a mechanicallinkage is formed and links 46 and 47 are allowed to slide within thelimits of the slotted socket opening 55. Referring to FIG. 12 and FIG.13, the curved profile 48 of retractable links 46 and 47 serve two majorpurposes; they are such that they resist the torsion experienced byinterlinkassembly 11 during operation; and serve to guide links 46 and47 outward during retraction to avoid interference with subsequentlink-base subassemblies. Link hinges 57 may be loaded with torsionalsprings to provide torque to the retractable links 46 and 47 in thedirection shown in FIG. 13 this encourages each retractable link topivot outward during retraction.

Each hinged plate 44 is hinged to link hub 40 by way of plate hingesockets 58 and plate hinges 54. Each hinged plate 44 extends from itshinged edge located on a first link hub 40 to a next link hub 40 suchthat its other unhinged edge rests on hub ledge 59 of the next link hub40. Referring now to FIG. 12 thru FIG. 18 hinged plates 44 are hingedsuch that they form the shape of an airfoil surface while rotor blade 02is extended and when the rotor blade 02 is retracted overlap one anotherlike shingles.

FIG. 13 shows the operation of locking mechanism 60. Referring to FIG.12 and FIG. 13 threaded screws holes 56 also serve as pin joints aboutwhich locking arms 45 are allowed to pivot. This is how the locking arms45 are able to be rotated to the unlocked position. The mechanism islocked by mechanical interference between locking ledge 49 located onlinks 46 and 47 and the distal edge of locking arms 45. Locking pinjoints 61 may be fitted with torsional springs which can be used toimpart a permanent torque to locking arms 45 as shown in FIG. 13. Thiswill ensure that the system defaults to the locked position. Releasecable 70 is connected to locking arms 45 such that translation ofrelease cable 70 causes locking arms 45 to rotate about locking pinjoints 61 and thereby clearing the mechanical interference and unlockingthe mechanism.

13. Retracting Reel Assembly:

Referring to FIG. 19 thru FIG. 21 and FIG. 39 the retraction reelassembly 13 can be thought of as concentric shafts where each shaftcontributes to the rotation, deceleration and/or retraction of the rotorsystem. The retraction assembly serves to unlock and retract each rotorblade 02. The retracting reel assembly 13 is comprising of an exteriorrotor axle 71; interior rotor axle 72; breaking actuator 73 wherebreaking actuator 73 has a plurality of breaking notches 77 located atits exterior surface and has an actuator chamfer 78 at its upper edge,the breaking actuator is positioned coaxially and in between exteriorrotor axle 71 and interior rotor axle 72, breaking actuator 73 is ableto rotate at a different rate relative to the exterior and interiorrotor axles; The retracting reel assembly 13 is also comprising of aplurality of recoiling spools 74 which form a reel cage 75 eachrecoiling spool has fitted within it a plurality of breaking pins 76each spool acting as a bobbin when the retraction cable is wrappedaround it, each release cable 70 has one end connected to the edge of arecoiling spool 74 and has the other end passed thru through hole 38 andis connected to locking mechanism 60 by way of locking arms 45. Therotation of reel cage 75 is neutral when not engaged by breakingactuator 73 and is allowed to rotate about the interior rotor axle 72.The reel cage is held within the rotor hub at the top by the upper partof interior rotor axle 72 and at the bottom by the exterior rotor axle71.

The motion of the reel cage 75 is allowed to be neutral when the rotorblades are to be extended. Upon spin-up of the system retraction reelassembly 13 experiences the same rotational speed as the rest of thesystem by way of the tension imparted by release cables 60. To initiateretraction of the rotor blades, the breaking actuator 73 is translatedvertically along its axis of rotation and is rotated at a differentrotational speed than the rest of the system such that it engages withand depresses the breaking pins 76 (FIG. 21). Each breaking pin 76 isfitted with a coaxially located helical spring 03 to provide a reactionforce against surface of breaking actuator 73. As breaking actuator 73is translated upward breaking pins 76 are guided into breaking notches77 by way of actuator chamfer 78. The breaking pins 76 are then forcedto translate radially outward while simultaneously being caught inbreaking notches 77. This action effectively stops the reel cage whichis released from a neutral condition and assumes the rotation ofbreaking actuator 73. The action of recoiling spool 74 also serves toactuate locking mechanism 60 in link hub 40. This action simultaneouslyunlocks locking mechanism 60 and develops a net force radially inwardwhich consequently causes retractable links 46 and 47 to slide throughslotted socket opening 55 and acts to retract the rotor blades inwardtoward the rotor hub 10. Reel cage 75 and each recoiling spool acts as abobbin onto which retraction cable 70 is coiled and the device is thenretracted.

Referring to FIG. 19 thru FIG. 21, each locking mechanism 60 is unlockedby a dedicated instance of release cable 70. One advantage of having adedicated release cable 70 for each locking mechanism 60 is the abilityto selectively unlock an individual locking mechanism 60 by modifyingthe geometry of breaking actuator 73 or the stacking order of recoilingspools 74 of reel cage 75.

14. Helical Ribbon Assembly:

The purpose of helical ribbon assembly 14 is to serve as the primaryaxial and tensile load bearing subassembly and to reinforce theinterlink base assembly and form a rigid structure over which a flexiblesleeve can be fitted. Another purpose for the helically wound ribbon isto constrict, lock and immobilize the interlink base assembly when it isin use and allow the interlink base assembly to retract when not in use.Referring to FIGS. 5, 6, 8, 10, 22 and 29, the helical ribbon assembly14 is comprising of a plurality of sequentially overlapped ribbons 80each ribbon having at one or both ends an end tab 81 and or a pluralityof end pins 82; each helically wound ribbon 80 is comprising of aplurality of laminated or woven layers; each ribbon is helically woundaround the interlinkassembly 11 and held at either extremity by way ofpin joints. Each ribbon is held to the interlinkassembly 12 by way ofend tab 81 and or end pins 82. In the figures helical ribbon assembly 14is connected at one end to the blade base 30 by way of pin joints 31 andis connected at the other end to a link-hub subassembly 12 by way of endpin 82. The purpose of end tab 81 is to provide a strong support to thelaminated or woven composite fibers of the braided ribbons. Thisprovides strength to the system during operation.

By having a crisscrossed braided pattern similar to a Chinese fingerlock braid and being helically wound at an angle to each other eachbraided ribbon 80 is capable of changing the radial diameter of thehelix which it forms. Upon retraction of the impeller blade assembly 02,helical ribbon assembly 14 is also retracted and recoiled as shown inFIG. 8. Each helical ribbon 80 is sequentially over lapped such thatthey form a virtually flat uniform surface when the system is in itsextended condition and when helical ribbon assembly 14 is retracted ittakes the profile of concentric spirals at the center of which is theretracted interlinkassembly 11. Referring to FIG. 29 one extremity ofhelical ribbon assembly 14 is guided during retraction and deployment byend pin 82; end pin 82 fits in the slotted pin joint 51 of link hub 40.

One possible embodiment of braided ribbon 80 comprises of a highstrength fiber layer sandwiched by two low friction layers; By beingconstructed in this way a plurality of braided ribbon 80 are able toslide with low friction relative to each and adjacent ribbons. Referringnow to FIG. 10 end tab 81 can be fitted with a torsional spring suchthat upon being rotated about pin joint 31 a torque is developed torestore end tab 81 to its original position.

Referring to FIG. 10 two end tabs 81 are arranged side by side toillustrate end tab cross sectional geometry 85. End tab cross sectionalgeometry 85 allows a plurality of end tabs 81 to be overlapped and/orarranged in proximity to each other and remain guided during rotationabout pin joints 31 and upon release return to their original positionsrelative to an adjacent end tabs 81. Consequently end tab crosssectional geometry 85 also ensures that each consecutive braided ribbon80 is retracted relative to an adjacent braided ribbon 80 and is able torecoil with out obstruction.

Referring to FIG. 24 and FIG. 25, the functions of the elastic slingmembrane 95 and elastic fiber membrane 96 are to serve as guiding andseparating interfaces between the components of helical ribbon assembly14 and flexible and elastic sleeve 15.

15. Flexible and Elastic Sleeve:

Referring to FIG. 24 thru FIG. 32 and FIG. 38 one possible embodiment ofelastic and flexible sleeves 15 is shown comprising of a plurality ofelastic ribs 101, elastic and flexible skin 90, and elastic slingmembrane 95. In this embodiment elastic and flexible skin 90 is acontinuous membrane comprising of an elastomeric sheet or series offibers which are laminated or woven and whose fibers are oriented atdiagonals to each other which allow the skin to change its aspect ratiodepending on the direction of the tension applied. The preferredembodiment of flexible skin 90 is made of fibrous, elastomeric, braided,and/or woven material, and/or any combination of the aforementionedmaterials to be a flexible membrane which serves as an exterior surfaceexposed to the airstream. Elastic and flexible skin 90 can be made of aplurality of composite layers. These composite layers can be constructedof braided composite fibers. These braided fibers can be woven to takeon beneficial patters which contribute to the strength and function ofthe system. FIG. 26 and FIG. 27 show representations of braided or wovenpattern 100 which is capable of being longitudinally extended andthereby changing the aspect ratio between the diameter and thelongitudinal span of the braided or woven pattern. By the use of abraided pattern 100 elastic and flexible sleeve 15 contributes to theconstriction experienced by interlinkassembly 11 and by helical ribbonassembly 14 when the system is in its extended condition and allows forrelaxation and expansion of the exterior skin when the system isretracted.

Elastic ribs 101 and elastic sling membrane 95 impart rigidity toelastic and flexible skin 90 while themselves being flexible andelastic. Upon retraction the use of elastic ribs 101 encourage organizedcorrugation of elastic and flexible sleeve 15. In other words due toelastic rib 101 upon being retracted elastic and flexible sleeve 15 willbe encouraged to ruffle. FIG. 4 and FIG. 8 illustrate interlinkassembly11, helical ribbon assembly 14 and elastic and flexible sleeve 15 intheir retracted states. In other words elastic and flexible sleeve 15conforms to profile 32 of interlinkassembly 11 when the rotor blade isin its extended condition and when the system is retracted the elasticsleeve is able to buckle or ruffle to a predetermined pattern which isable to envelope the retracted interlinkassembly and retracted helicalribbon assembly.

Referring to FIGS. 19, 20, 23, 24, 25 and FIG. 29 a second embodiment ofelastic and flexible sleeve 15 is disclosed. The flexible and elasticsleeve 15 comprising of an elastic and flexible skin 90 which is made upof laminated or woven composites and having a sleeve lip 97; a sleeveretainer ring 92 which holds the sleeve lip onto the blade base 30 andprevents the sleeve from sliding off the rotor blade during rotation; aplurality of elastic trailing edge strips 91; a plurality of zipperteeth 93 which are spaced along a zipper web 94 such that a zipperclosure is formed between a top zipper half and a bottom zipper halfwhere both halves extend along an upper and lower longitudinal edge offlexible and elastic skin 90; an elastic sling membrane 95 and/or anelastic fiber membrane 96. Referring to FIG. 23, the zipper teeth areconnected to the zipper web by crimping one edge of the zipper teeth 93along the zipper web 94.

Referring to FIG. 23 and FIG. 24, at a top longitudinal edge and at abottom longitudinal edge of the elastic and flexible skin 90 there isconnected a top and a bottom elastic and flexible trailing edgesubassembly. The flexible trailing edge subassembly is comprising of aplurality of elastic and flexible trailing edge strips 91 which areindividually laminated or extruded to form longitudinal sections of arotor blade's trailing edge and are fastened along one edge to eachother to form an upper trailing edge and a lower trailing edge. When therotor blade is in its extended condition and the zipper closure is inits fastened or zipped condition the aforementioned components form arigid airfoil trailing edge. The trailing edge subassemblies can beconstructed by way of adhering or stitching each correspondinglongitudinal edge of the zipper web 94 to a corresponding longitudinaledge of the elastic skin 90 and to the longitudinal edge of the flexibletrailing edge strips 91 thereby creating a seam which serves as apermanent fastening between them. Each individual layer 91 of thetrailing edge subassembly is stiff enough that when stacked togetherthey form a rigid structure and are flexible enough that when retractedare able to buckle and ruffle.

Referring now to FIG. 24 and to an additional embodiment of elasticmembrane 95 which is folded along its length to form a pleated accordionpattern with a top longitudinal edge of the accordion pattern connectedto the longitudinal edge of a top zipper web 94 and at the bottomlongitudinal edge of the accordion pattern connected to the longitudinaledge of a bottom zipper web 94. Referring to FIG. 19, FIG. 24 and FIG.32 the inner face of elastic sling membrane 95 comes in direct contactwith the exterior surface of helically wound ribbon assembly 14 and onits other face comes in contact with the inner surface of the zipperwedge 111. This configuration creates a barrier between the helicalribbon assembly 14 and the main zipper slider 110. In this way elasticmembrane 95 acts as a guiding interface between helical ribbon assembly14 and the zipper closure formed by zipper teeth 93. This allowsflexible and elastic sleeve 15 to buckle over the interlinkassembly 11and helical ribbon assembly 14 while retaining its ability to return toits prior condition and shape when the system is extended or retracted.Another use for the elastic membrane 95 is to guide the top and bottomzipper teeth during opening and closing of the zipper system and alsoserves to prevent snags, misalignment and interference of the zipperteeth 93.

Referring to FIG. 25, elastic fiber membrane 96 is shown serving thesame function as elastic sling membrane 95 and is shown to be made up offibers oriented one across the other with one extremity of the eachfiber connected to a top zipper web and the other end connected to abottom zipper web. In this way a webbed matrix which connects the topand bottom sections of the elastic sleeve is formed. Interlocking tongueand groove geometry 98 shown in FIG. 30 and FIG. 31 and hook and hollowgeometry 99 shown in FIG. 28 represent additional possible closure typesfor flexible and elastic sleeve 15.

16. Zipper Slider Mechanism:

Referring now to FIG. 5, FIG. 19, and FIG. 33 thru FIG. 35 a firstzipper slider mechanism 16 is shown comprising of a main slider 110encompassing flexible sleeve 15 and serving as the primary means bywhich the closure formed by flexible and elastic sleeve 15 is zipped andunzipped. The major features which enable the main slider's function area zipper wedge 111 located on the inner surface of the main slider'strailing edge and having a top and bottom wedge track 112 which serve toguide the zipper teeth 93 during extension and retraction of the rotorblade; a first spring loaded wheel 113 located at the top of the innersurface of the main slider; and a second spring loaded wheel 114 locatedat the bottom of the inner surface of the main slider; and a thirdspring loaded wheel 115 located on the inner surface of the mainslider's leading edge where each spring loaded wheel serves to assist inthe retraction of the flexible and elastic sleeve15 by way of a springpotential which is generated during extension of the rotor blades andcaused by mechanical friction between the spring loaded wheels and theexterior surface of the flexible skin 90; a first hinged plate 116having one end hinged to the top of the main slider and the other endhinged to the inner surface of the top rotor casing 21; and a secondhinged plate 117 having one end hinged to the bottom of the main sliderand the other end hinged to the inner surface of the bottom rotor casing22.

The main slider 110 serves the same function as a conventional zipperslider whereby being translated along the length of the rotor blade 02it opens and closes the zipper closure created by the flexible andelastic sleeve 15. Referring now to FIG. 20 and FIG. 21, a first hingedplate 116 is connected to the top hinged blade casing 21 by way of tophinge connection 28 and to the main slider 110 by way of top sliderhinge 118. A second hinged plate 117 is connected at one end to theblade bottom hinged casing 22 by way of a bottom hinge connection 29 andat the other end to the main slider 110 by way of a slider bottom hinge119. When the system is at rest and in its retracted condition as shownFIG. 21 upon applying a rotational acceleration to the system the topand bottom casings 21 and 22 begin to rotate about their correspondinghinged connections to the hub wall 20, this motion causes the anglesbetween the hinged plates and the blade casings to be altered andthereby cause the main slider 110 to be translated along the span of therotor blade.

Referring to FIG. 19 and FIG. 35 spring loaded wheels 113, 114 and 115are equipped with torsion springs whereby extension of the rotor bladeassembly causes the spring loaded wheels to develop a potential to rollthe elastic and flexible sleeve 15 back to its prior condition. Theroller wheels also impart a frictional force to the trailing edge zipperserving to assist in guiding the zipper teeth 93 along the wedge track112 and upon unlocking the assembly and in the absence of a rotationalforce assisting to return the assembly to its contracted state. FIG. 32shows how spring loaded wheels 113,114,115 and wedge track 112 worktogether to guide zipper teeth 93 during retraction and extension.

Referring now to FIG. 36 and FIG. 37 a second embodiment of the zipperslider mechanism is disclosed. In this embodiment the main slider 110has a circular exterior profile and is coaxial to and encompassed by acircular ring bearing 121. Where the ring bearing 121 is hinged at itsupper and lower extremities to the top and bottom blade casingsrespectively. The purpose of the ring bearing is to allow the mainslider to rotate about its longitudinal axis in unison with and inresponse to the rotation of pitch disc 23.

Operation of the Retractable Rotor Blade.

When the engine of the vehicle (aircraft) is energized the hub rotatesand a centripetal force is developed, the rotor blade assembly isexpanded by centripetal force acting on the components which are free tomove, that is, the rotor blade is extended radially outward from theaxis of rotation. During the expansion of the rotor blade the followingoperations occur. The distal tip of the rotor blade starts to extendradially outward and the zipper slider mechanism brings the upper andlower trailing edges of the flexible sleeve's zipper together andthereby closes the zipper as it extends outward.

At the same time, during the expansion process the interlink assemblyalong with each link base subassembly, through the rotation of theirhinged linkages, are allowed to extend radially outward and engage thelocks in the link hub 40, through the locking ledge 49 engaging with thelocking arm 45. Also at the same time the elastic sleeve and the helicalribbon assembly are extended outward, by way of centripetal force andmechanical connections to the interlink assembly, and develop aconstricting effects which serves to rigidify the rotor blade. Thecombination of the locking mechanism, the elastic sleeve and the zippersystem provide a flexural and lateral bending stiffness and rigidity tothe rotor blade which is required for a lift action on the aircraft.

When the rotational speed of the engine is reduced and the aircraftbegins to be stopped the centripetal force is reduced and approaches tozero. At the same time the retraction reel assembly 13 and breakingactuator 73 (component of the rotor blade 02) through the release cables70, unlock and pull the interlink assembly radially inward towards thecentral axis 72. Also at the same time during the retraction process thezipper slider mechanism unzips the flexible sleeve as it is beingretracted and serves to guide the helical ribbon assembly back to theirretracted conditions. These operation leads to a retracted rotatorblades system.

While the foregoing written description of the invention enables one ofordinary skill to make and use what is considered presently to be thebest mode thereof, those of ordinary skill will understand andappreciate the existence of variations, combinations, and equivalents ofthe specific embodiment, method, and examples herein. The inventionshould therefore not be limited by the above described embodiment,method, and examples, but by all embodiments and methods within thescope and spirit of the invention as claimed.

REFERENCE NUMERAL LIST

-   02. Rotor Blades-   03. Helical Spring-   04. Torsion Spring-   05. Bolts/screws-   10. Rotor Hub-   11. interlinkAssembly-   12. Link Base Subassembly-   13. Retracting Reel Assembly-   14. Helical Ribbon Assembly-   15. Flexible and Elastic Sleeve-   16. Zipper Slider Mechanism-   20. Rotor Hub Wall-   21. Blade Top Hinged Casing-   22. Blade Bottom Hinged Casing-   23. pitch disc-   24. Push Rod-   25. Moment Arm-   26. Rotor Hub Top Casing-   27. rotor hub bottom casing 27-   28. top hinge connection-   29. btm hinge connection-   30. Blade Base-   31. Pin Joints-   32. Characteristic Profile-   33. Pneumatic damper & Cable Casing-   34. Guide Notch-   35. blade base rectangular slots-   36. collapsible corrugated geometry-   37. slotted cylindrical section-   38. thru hole-   40. Link Hub-   41. Top Link Hub-   42. Bottom Link Hub-   43. Through Hole-   44. Hinged Plates-   45. Locking Arms-   46. first Retractable Link-   47. second retractable Link 2-   48. Curved Profile-   49. Locking Ledge-   50. hub Hinge-   51. Slotted Pin Joint-   52. Link Heads-   53. Link Head Groove-   54. Plate hinge-   55. Slotted Socket Opening-   56. Threaded screw holes-   57. link hinges-   58. plate hinge socket-   59. hub ledge-   60. locking mechanism-   61. locking pin joint-   62. plate pin joint-   70. Release Cable-   71. Exterior rotor axle-   72. Interior Rotor axle-   73. Breaking Actuator-   74. Recoiling Spools (plurality)-   75. reel cage-   76. Breaking Pin-   77. Break Notch-   78. Actuator Chamfer-   80. Braided Ribbon-   81. End Tabs-   82. End Pin-   83. Sequentially Overlapped-   84. Strength Layer-   85. end tab cross sectional geometry-   90. Elastic and Flexible Skin-   91. Elastic and Flexible Trailing Edge strips-   92. sleeve Retainer Ring-   93. Zipper Teeth-   94. Zipper Web-   95. Elastic Sling Membrane/folded accordion membrane-   96. Elastic fiber membrane-   97. sleeve lip-   98. Interlocking Tongue and Groove Geometry-   99. Hook and Hollow Geometry-   100. Braided or woven Pattern-   101. Elastic Rib-   110. Main Slider-   111. Zipper Wedge-   112. Wedge Track-   113. first Spring Loaded Wheel 1-   114. second Spring Loaded Wheel 2-   115. Spring Loaded Wheel 3-   116. first Hinged Plate 1-   117. second Hinged Plate 2-   118. top slider hinge-   119. bottom slider hinge-   120. Hinge Joint 1-4-   121. zipper slider ring bearing.

1. A retractable impeller assembly for providing vertical lift to avehicle comprising; a plurality of rotor blade where each rotor bladecomprising: (i) a rotor hub assembly comprising of a rotor hub wall, ablade top hinged casing, a blade bottom hinged casing, a pitch discwhich is able to rotate about its longitudinal axis and having a momentarm means, a push rod, a rotor hub top casing, a rotor hub bottomcasing; (ii) an interlinkassembly comprising of a blade base having aplurality of pin joints, guide notches, blade base rectangular slots andthru hole, a characteristic profile, a pneumatic damper and cable casinghaving collapsible corrugated geometry and a slotted cylindricalsection, a plurality of link base subassemblies which are repeatedsimilar to links in a standard chain; (iii) a link base subassemblycomprising of a top link hub, a bottom link hub where together form alink hub, a characteristic profile, two locking arms and a plurality ofplate hinge sockets, a first retractable link and a second retractablelink both with a curved profile, a plurality of hinged plate; (iv) aretracting reel Assembly comprising an exterior rotor axle, an interiorrotor axle, a breaking actuator having a plurality of breaking notcheslocated at its exterior surface, a plurality of recoiling spools whichform a reel cage; (v) a helical ribbon assembly comprising a pluralityof sequentially overlapped ribbons where each ribbon having at one orboth ends an end tab and or a plurality of end pins, a plurality oflaminated or woven layers where each layer is helically wound aroundsaid interlinkassembly and is held at either extremity by way of pinjoints, a plurality of pins where they restaine each ribbon to saidinterlinkassembly; (vi) a flexible and elastic sleeve comprising aplurality of elastic ribs, an elastic and flexible skin made ofcomposite elastomeric sheet reinforced by woven or braided fibers; and(vii) zipper slider mechanism comprising a main slider, a zipper wedge,a wedge track, a plurality of spring loaded wheels, a plurality ofhinged plates, a plurality of hinge joints.
 2. The apparatus forvehicle's vertical lift of claim 1 wherein the rotor blades and therotor hub casings are extendable and retractable and in their retractedconfiguration they require minimal space to be stowed away.
 3. Theapparatus for vehicle's vertical lift of claim 1 wherein the link basesubassembly is extended and contracted through hinged plates and curvedlinkage.
 4. The apparatus for vehicle's vertical lift of claim 1 whereinthe base subassemblies are covered.
 5. The apparatus for vehicle'svertical lift of claim 1 wherein the retraction reel assembly hasconcentric shafts where each shaft contributes to the rotation,deceleration and/or contraction of the rotor blades system, saidretraction reel assembly also serves to unlock and retract each rotorblade.
 6. The apparatus for vehicle's vertical lift of claim 1 whereinsaid helical ribbon assembly having a crisscrossed braided pattern andbeing helically wound similar to a Chinese finger lock braid and whereprovide bending stiffness of the rotor blades.
 7. The apparatus forvehicle's vertical lift of claim 1 wherein said flexible and elasticsleeve provides an exterior surface exposed to the airstream and can bemade of a plurality of composite layers with plurality of ribs andbraided composite fibers.
 8. The apparatus for vehicle's vertical liftof claim 1 wherein said zipper slider mechanism which encompasses saidflexible sleeve and forms a closure by zipping and unzipping, during theextension and contraction of the rotor blade, the zipping and unzippingis performed by a wedge located on the inner surface of the mainslider's trailing edge, the wedge shape being a tongue and groove or anycoupling parts.